Fill a medium-size bowl with cold water. Scrub the potatoes well under running water. I like to leave the skin on since it looks pretty. Shred the potatoes through the large holes of a box grater, the fine teeth of a mandoline, or the shredding disk of a food processor. Submerge the shreds in the bowl of water to rinse off the surface starch.
Pour the masa harina into a medium-size bowl and add the salt, cilantro, and chile.
Drain the potatoes in a colander and rinse them under cold running water to remove any remaining excess surface starch. Give the colander a good shake or two to rid the potatoes of excess water.
Add the potato shreds to the masa and give it all a good mix. (I use my hand.) Mix in 1 cup of the hot water. It should start to come together to form a bumpy-textured dough. Add more hot water ¼ cup at a time, making sure it gets incorporated well. The dough should feel bumpy but soft, like a textured Play-Doh, a bit grainy to the touch.
Lay out a large sheet of wax paper or parchment paper on the counter. Wet several sheets of paper towels. Break up the dough into 16 equal portions and set them on the wax paper. Roll each portion into a ball. Keep them securely covered under wet paper towels. The moisture from them will continue to keep the dough moist.
When youre ready to cook the tortillas, preheat a medium-size nonstick skillet or heavy cast-iron pan over medium heat. Cut a 14-inch-square piece of parchment paper or wax paper and fold it in half. Place a dough ball inside its fold and flatten it either with a rolling pin or by pushing down on it with a pie plate. You want a circle roughly 6 inches in diameter. If you have a tortilla press, by all means, use it.
Gently pull off the paper and place the tortilla in the hot skillet. It will start to bubble up in places and the underside should have brown patches in 3 to 4 minutes. Flip it over and cook the other side an additional 2 minutes. Transfer it to a plate and cover it with a piece of aluminum foil or a clean kitchen towel. Repeat with the remaining dough. Its important to keep the cooked tortillas covered because the heat from within creates steam that makes them soft and pliable. Serve them warm.
To make the tacos, set a large skillet over medium-high heat with the olive oil. Once hot, add in the diced potatoes and cook, stirring often, until the potatoes are golden brown, crispy and cooked through, about 15 to 20 minutes. Add in the soyrizo and cook until warmed through.
Assemble the tacos by filing the potato tortillas with the potato chorizo mixture and then top with cilantro, avocado, pickled jalapeños, and cheese. Enjoy!